Mr. Kelly talked of a new antigang strategy. Then he shrugged and smiled.

“In my business, in our business, this is miraculous,” he said. “These are lives being saved.”

“Miracle” is an appropriate word for the fact that nearly 1,800 fewer New Yorkers might be murdered this year than in 1990. But with all due respect to perhaps the nation’s finest urban police force, we have become too reductive. Nearly every drop in crime is attributed to this or that police strategy.

This fails to reckon with a more intriguing sea change to be found in neighborhoods once marked by shootings and mayhem. Blocks surrendered to the rubble of abandonment have been rebuilt with city dollars; teenage girls are having fewer children and are far less likely to turn to welfare; drug overdose deaths and prison populations have dropped sharply, and life expectancy and homeownership in these neighborhoods has risen sharply.

In the early 1980s, I worked as a tenant organizer in East Flatbush, a once-white working-class neighborhood that had nearly overnight become home to working-class black immigrants from across the Caribbean. Storefronts had been abandoned; Rastafarian weed dealers walked me out of an apartment building they had colonized. At night I could hear the high pitched whine as, behind closed metal gates, Utica Avenue chop shops turned stolen cars into marketable parts.

It was a neighborhood perched on a chasm’s edge.

I drove back recently and stopped on East 37th Street, where I ran into Godfrey Sandiford, 68, walking the block like the de facto mayor he is. Homes there are freshly painted, with rebuilt stoops and shiny brass fences. Hydrangeas and crotons and roses and lilies explode beneath the shade of sycamores.

Mr. Sandiford is the block association president and serves on the precinct council. He recalls the shootings and lootings of the ’80s, the buses that barely ran, the feral children. “We had our doubts, yes we did,” he says.

Mr. Sandiford and his fellow residents did not run. They formed block associations (many now fly handsome flags announcing their presence), and tenants fought for heat and hot water and front doors that locked. Police officers became their partners, marching with them step by step. But Mr. Sandiford, who arrived in New York in 1965 from Barbados, is not inclined to shortchange his fellow residents.

Photo

“These are our homes and our streets and we fought for them,” said Godfrey Sandiford, 68, of East 37th Street in the East Flatbush area of Brooklyn.Credit
Jabin Botsford/The New York Times

“I have the greatest respect for our police, but I know this for a fact: New Yorkers deserve the bulk of the credit,” he says. “These are our homes and our streets and we fought for them.”

Along the way, New Yorkers themselves changed significantly. Far fewer children tumble into the maw of foster care, as more than 50,000 did in 1991, compared with less than 13,000 today. In 1990, 11.6 infants per 1,000 live births died; in 2011, the number of such deaths had fallen to 4.7.

I wandered around the corner to Farragut Road, where the Bloomberg administration, with quiet and grand initiative, recently planted several baby oaks. Pearl Brome, a proud homeowner once from Trinidad, puts on her straw hat. She and her neighbors are installing fences and planting flowers around these young trees.

I made a final stop this morning, driving to East New York, which in 1990 was a violent caldron. Gangbangers, with unapologetic shrugs, talked of shooting mushrooms — street slang for the bystanders who popped up in the middle of gunfights.

Near Spring Creek, East Brooklyn Congregations, a neighborhood alliance, has built fine rows of prefabricated town houses that would not look out of place in a trendy Berlin neighborhood. The Metropolitan Transportation Authority agreed to run a new express bus from here to the No. 3 subway line in East New York. There are new schools, supermarkets, parks, apartment buildings.

Michael Gecan of E.B.C. has organized here for decades. He is not inclined to discount the police. They helped to reclaim these streets, opened the door for the civic change that has transformed a city.

Neither, however, is he inclined to discount his own members, the pastors, teachers, nurses, transit workers and small-business owners who, at great risk to themselves, worked with the police to identify drug dealers and gangbangers and so reclaim this territory.

“Good reinforces good reinforces good,” he says. “We’re approaching that exalted state known as normal.”

And isn’t that another miracle of sorts?

E-mail: powellm@nytimes.com

Twitter: @powellnyt

A version of this article appears in print on July 16, 2013, on Page A15 of the New York edition with the headline: Stalwart Citizens, Not Just Police Tactics, Deserve Credit as Crime Ebbs. Order Reprints|Today's Paper|Subscribe